Angle of repose valves have typically been used for granular materials in order to interrupt the flow of granular material. While these valves can be adapted for use at high temperatures, the valves may not provide a sufficiently gas tight closure, and for many applications must ba used in combination with a secondary sealing valve when gas-tight closure is required.
An improvement in the handling of granular or abrasive materials was achieved with an inflatable seat valve having a spherical shaped shell closure for interrupting the flow of granular materials. U.S. Pat. No. 4,137,935 describes such a valve assembly. Typically, such inflatable seat valves are not suitably designed for very high pressure and/or high temperature applications involving pressures in the range of from 200 to about 400 psi (1.4 to about 2.8 MPa) and/or temperatures in the range of from about 150.degree. C. to about 250.degree. C.
Accordingly, it is an object of the invention to provide an improved inflatable seat valve for handling granular and/or abrasive materials.
Another object of the invention is to provide a valve assembly which performs satisfactorily at temperatures as high as about 350.degree. C.
Yet another object of the invention is to provide an improved inflatable seat valve assembly which performs well in applications involving pressures as high as about 600 psi (4,000 kPa).
A further object of the invention is to provide a valve assembly having an inflatable seat for applications involving pressures as high as about 600 psi (4,000 kPa) and temperatures as high as about 350.degree. C.
An additional object of the invention includes provision of a valve assembly which may be assembled in a manner which enables the use of precision machined parts for high pressure applications without imposing any significant radially directed impact forces upon the shaft, bearings and seals.
Still other objects of the invention will be evident from the ensuing description and appended claims.